The present invention relates to endoscopes (including devices such as borescopes, fiberscopes, etc.) and specifically to control of endoscopes capable of varying their direction of view.
Endoscopes are elongated devices used to visualize the insides of cavities. Recent developments have brought about endoscopes capable of varying their direction of view. The purpose of these endoscopes is to allow the user to scan over a larger area with less device movement than traditional endoscopes and provide greater flexibility in obtaining a desired view.
Most endoscopes capable of varying their direction of view include mechanically steered optical components. These are controlled using one or more knobs or similar devices for adjusting the degrees of freedom available in the endoscope along the respective axis of each degree. Examples of these are disclosed in U.S. Pat. No. 3,880,148 to Kanehira et al. (1975), U.S. Pat. No. 4,697,577 to Forkner (1987), U.S. Pat. No. 3,572,325 to Bazell et al. (1971), and WIPO publication WO 99/42028 by Heg et al. (1999). In all of these examples, each axis of adjustment is controlled independently. Making a desired compound adjustment involving two or more axes is difficult to accomplish, requiring multiple hands and/or great dexterity.
Other endoscopes capable of varying their direction of view include those disclosed in U.S. Pat. No. 5,954,634 to Igarashi (1998) and U.S. Pat. No. 5,313,306 to Kuban, et al. (1994). These devices provide a viewed area variably selected from within a wide-angle captured image giving a result similar to those with mechanically adjusted optical components. Like mechanically adjusted variable direction of view endoscopes, these devices may only be adjusted in a predetermined manner with predetermined axes.
Each of the above endoscopes has a set of adjustment axes that define a natural coordinate system for that endoscope. In the natural coordinate system, each degree of freedom of the endoscope is one axis of the coordinate system. Each endoscope is controlled in relation to its natural coordinate system. Due to differences in the design of varying endoscopes, each endoscope""s natural coordinate system may be different. This can create a significant problem for users when attempting to work with a different endoscope than that which they are accustomed to. The natural coordinate system of an endoscope is always aligned with that endoscope rather than with the user""s surroundings or the operating cavity. The user can become confused when trying to selectively scan within a coordinate system that fails to align with a familiar environment.
Because the distal end of a variable direction of view endoscope is generally not visible during use, the user often requires an external indication of the current viewing direction. Some endoscopes fail to have any method of indicating the direction of view, while others include indicators that are inconvenient or difficult for the user to interpret. Not knowing the current direction of view makes it challenging to adjust to a desired direction of view or find a particular feature within the cavity. Additionally, returning to a previous direction of view can be quite challenging.
Although prior art variable direction of view endoscopes may have been designed for easy and efficient use, the interfaces heretofore known suffer from at least the following disadvantages:
a. The interface provided with each endoscope can be unintuitive and confusing for the user.
b. The disjoint control of multiple degrees of freedom makes precision compound adjustments prohibitively difficult to execute.
c. Various types of variable direction of view endoscopes require very different methods of operation.
d. The coordinate system available can not usually be aligned with the user""s surroundings.
e. The coordinate system available can not usually be aligned with the operating cavity.
f. The current direction of view can be difficult to determine.
g. The user must manually adjust the endoscope to return to a particular direction of view.
Some endoscopic control systems include actuators such as motors to assist the user in controlling the view. For example, U.S. Pat. No. 5,524,180 to Wang et al. (1996) discloses a motorized control system for automated positioning of an endoscope. Such control systems utilize a computer and robotic arm to control the movement of an endoscope for the purpose of changing the viewing direction. However, instead of moving the entire endoscope, variable direction of view endoscopes should be controlled in a way that utilizes their internal direction of view adjustment systems. Therefore, existing electro-mechanical endoscope control systems are not well suited to situations in which the use of a variable direction of view endoscope is desired.
Accordingly, the primary object of the present invention is to provide an easy-to-use interface for a variable direction of view endoscope capable of adjusting multiple degrees of freedom of the endoscope simultaneously to execute precision compound adjustments. Another object of the present invention is to use this interface to mask the specific implementation of the endoscope from the user through a standard set of displays and controls. Yet another object of the present invention is to provide an interface having several different control coordinate systems for the user to choose between, enabling more efficient and effective procedures.
Still further objects and advantages will become apparent from the ensuing description and drawings.
In accordance with the present invention, an interface for a variable direction of view endoscope comprises an input means for receiving commands from the user, an output means for adjusting the endoscope, and an electronic processing device to determine the appropriate output based on the given input. In certain embodiments, the processing device may be configured to allow operation-assisting features including:
a. a control coordinate system aligned with the endoscope;
b. a control coordinate system aligned with the current view;
c. a control coordinate system aligned with the user""s surroundings;
d. a control coordinate system aligned with the operating cavity;
e. a clear display of one or more coordinate systems;
f. a memory to facilitate the immediate return to a user selected direction of view; and
g. a clear indication of the current direction of view.
The term xe2x80x9cendoscopexe2x80x9d as used herein is defined as an endoscope (used for medical procedures) or any similar device such as a borescope, a fiberscope, etc. The term xe2x80x9cendoscope configurationxe2x80x9d used herein is defined as a set comprised of an orientation (or state) of each axis (or degree of freedom) of a endoscope. The term xe2x80x9ccontrol coordinate systemxe2x80x9d is defined as the coordinate system with respect to which control inputs are made and interpreted. The term xe2x80x9cnatural coordinate system of an endoscopexe2x80x9d is defined as a coordinate system defined by the adjustment axes of an endoscope and may be used to parameterize a viewing direction and orientation with respect to the normal operation of that endoscope. The term xe2x80x9ccurrent view coordinate systemxe2x80x9d is defined as a coordinate system which is always aligned with the current viewing direction and orientation. An arbitrary coordinate system may be any other coordinate system related to the endoscope.
What is claimed is an interface for use with a variable direction of view endoscope, wherein a distal portion of said endoscope is disposed within a cavity, comprising an input means for receiving commands from a user, a tracking means for providing view vector orientation information, a processing means for receiving said commands and said orientation information and performing operations, comprising the calculation of a coordinate system that can change in alignment with said endoscope, and a viewing means for providing a current endoscopic view.